The use of turbochargers to increase engine performance is well known. Simply put, turbochargers increase the mass of air supplied to an engine, resulting in improved engine performance.
A typical turbocharger comprises a turbine wheel connected to a compressor impeller by a rotatable shaft. Hot engine exhaust gas powers the turbine wheel which drives the compressor impeller. The compressor impeller draws in relatively cool ambient air and compresses it before it enters the engine intake manifold.
The compressor impeller is housed within a compressor housing, and the clearance between the compressor impeller and the housing is extremely small. Compressor impellers operate at very high speeds, often up to 90,000 RPM in large turbochargers used in some heavy duty vehicles and up to 250,000 RPM in automobiles. Over time the compressor impeller can contact the compressor housing and cause scratches or grooves, some over 1 mm deep, which can reduce turbocharger performance or, worse, cause turbocharger failure. Replacing the compressor housing with a new housing is expensive.
The present disclosure is directed toward solving one or more of the problems set forth above.